PRIME Minister John Key expects to fly to Australia early next month for talks with election winner Tony Abbott.

Mr Abbott will by then have been sworn in as Australia’s new prime minister and Mr Key says he’s going to make a one-day trip soon after he returns on September 29 from visiting Europe and the US.

“This is our most important relationship,” he said on Monday.

“It’s a relationship that’s incredibly multi-faceted, New Zealand has an engagement with Australia from war to sport and it makes sense for us to get together.”

Mr Key expects to have lunch or dinner with Mr Abbott.

“That will be it – it will be partly an opportunity to talk about a whole range of things, setting out the work program makes sense,” he said.

Mr Key called Mr Abbott on Sunday to congratulate him.

“That provided an opportunity to reiterate the very strong relationship that underpins our country and I look forward to having a very positive working relationship with Tony Abbott’s government over the coming years.”